With the continuous development of electronic apparatuses towards super micromation, as well as the development of new computer, microelectronics, optoelectronics and communication theory and technology, the new wearable computing model of the concept that computing should adapt to human needs and contribute to the combination between human and machine has become possible. Wearable computing applications emerge in fields of military, industrial, medical, education, consumption and so on. In a typical wearable computing system architecture, the head-mounted display is a key component, which directs video image light emitted by the miniature image display apparatus (e.g. transmissive or reflective liquid crystal display, organic electroluminescent apparatuses, DMD apparatuses) to the user's pupil via the optical technology, and forms virtual and magnifying images in the near eye range and provides the user with intuitive and visual image, video and text information.
In order to achieve a better display effect, the head-mounted display should be tightly attached to the user's eyes and face around when being worn, such that the user having poor eyesight cannot use glasses while wearing the head-mounted display. Accordingly, the user can only watch relatively vague pictures, thus greatly affecting the user experience.
The prior art has disclosed an eyepiece structure capable of adjusting the visibility precisely through an eyepiece tube, an eyepiece base connected with the eyepiece tube via multiple screw threads, an eyepiece base backing ring sleeved on the eyepiece base, an eyepiece group embedded in the eyepiece base, a retaining ring provided with a groove, and other structures such as a positioning groove, a positioning bead and so on. Although the precise visibility adjustment of the eyepiece structure can be achieved by such manner, however no disclosure about how to realize the adjustment of the distance between the bilateral eyepieces, namely the interpupillary distance adjustment, by coordinating the visibility adjustment structure with other structures in bilateral eyepieces is exposed.
In another prior art, a head-mounted display is disclosed, in which the diopter and interpupillary adjustments are achieved via an X-axis bracket and a Y-axis bracket to adapt the user with different visual conditions. In this scheme, two lens tubes are driven to slide along X-axis direction on the X-axis bracket to adjust the center distance between the two lenses for adapting the users with different interpupillary distances. A Y-axis adjustment component is used for driving the X-axis bracket to slide relative to the Y-axis bracket along the Y-axis direction for adjusting the longitudinal distance between the two lenses and the display panel.
In yet another prior art, an adjustable head-mounted display is disclosed, in which scheme, a diopter adjustment component is provided on the main frame for adjusting the distance between the front lens tube and the back lens tube of the lens group at each side separately, and an interpupillary adjustment component is also provided for interpupillary adjustment. When the interpupillary adjustment turntable rotates, two transmission elements are brought to move leftward and rightward synchronously via the center gear for adjusting the distance between the front lens tubes of the lens group at the two sides, thus achieving the interpupillary adjustment of the head-mounted display.
The second and third schemes can achieve the visibility (diopter) adjustment and interpupillary adjustment at the same time. However, both of the lenses or lens tubes at both sides should be moved at the same time to adjust the interpupillary, which not only results in complex structure and large volume, but also results in the misplacement between the optical center and the display center thus directly affecting the display effect at the screen edge, as there is just one display screen whose effective display picture may be moved relative to the lenses or lens tubes at both sides during the interpupillary adjustment. Meanwhile, during the diopter adjustment, the movement of the lenses or lens tubes would change the distance between the lenses or lens tubes and the display screen at the same time, while changing the distance between the human eyes and the lenses or lens tubes, that is, changing the eye distance. However, the change of the eye distance would reduce the adjustment precision of the diopter thus affecting the viewing performance.
In additional, as the head-mounted display of compact size, light weight, convenient wearing and lighten load and so on is the development trend, the complicated structure is bound to result in increased volume and weight of the head-mounted display, thereby affecting its use effect.